Various procedures have been described for the exchange of obstructed drainage catheters while maintaining access between the organ to be drained and the patient's skin surface through the original percutaneous tract, i.e., the original pathway of the very first drainage catheter installed in the patient. Descriptions of such prior art drainage catheters, and particularly descriptions of special methods and equipment developed for exchange of obstructed or occluded drainage catheters, indicate the frequent complexity of such exchange procedures and their attendant treatment times, likely patient discomfort and relative risk factors.
Representative descriptions of drainage catheter exchange procedures can be found in the following publications:
1) Use of flexible, 22-gauge Trocar Needle and an Obturator for Obstructed Drainage Catheter Exchange; G. L. McLellan; American Journal of Radiology, 151: 521-522; September 1988. PA1 2) Exchange of Occluded Catheters with Transcatheter and Pericatheter Maneuvers; A. S. Lee, E. van Sonnenberg, G. R. Wittich, G. Casola; Radiology, 163: 273-274; April 1987. PA1 3) Replacement of Obstructed Loop and Pigtail Nephrostomy and Biliary Drains; C. Cope; American Journal of Radiology, 139: 1022-1023; November 1982. PA1 4) Exchange of an Obstructed Loop Nephrostomy Catheter; F. C. Cazenave, M. C. Glass-Royal, K. H. Barth; Cardiovascular and Interventional Radiology, 13: 327-328; 1990.
In contrast to complex drainage catheter exchange procedures of the prior art, the present invention provides improved drainage catheter systems (method and apparatus) for easy exchange by means of a pre-installed obturator in an obturator channel, which may be integral to the catheter system, and which is installed as a part of the catheter system.
Accordingly, it is a feature of the invention to provide a drainage catheter system having at least one main drainage lumen for draining fluid from an organ whose natural drainage pathway is blocked, and having as a component of the catheter system an obturator channel sealed by an obturator which is removed just prior to exchange or replacement of an initially installed and obstructed or occluded drainage catheter system of the present invention by a new drainage catheter system of the present invention.
It is another feature of the invention to provide easy exchange of an obstructed or occluded drainage catheter system through the original percutaneous tract.
It is a further feature of the invention to provide the easy exchange of drainage catheter systems by use of a conventional flexible-tip guidewire.
It is a still further feature of the invention to provide release means associated with the obturator for releasing a drawstring or retaining thread from its catheter loop-retaining position, thereby freeing the catheter loop from retention and readying the drainage catheter system for the exchange procedure.
Briefly described, the present invention provides an easily exchanged drainage catheter system for drainage of fluids from organs such as, for example, a kidney or a liver, or from abscesses. When obstruction or occlusion of the main drainage lumen of the initially installed catheter system requires exchange or replacement, a sealingly fitting obturator is fully withdrawn from an obturator channel integral to the drainage catheter system. In accordance with an aspect of the invention, the obturator as it is withdrawn from the channel, firstly releases a taut drawstring or retaining thread or other retainer of the looped distal end of the drainage catheter. When withdrawn, the obturator provides an open or unobturated channel between the organ to be drained and the outside of the patient's skin surface. A conventional flexible-tip guidewire (of diameter slightly smaller than the diameter of the unobturated channel) is inserted through the open channel, preferably under fluoroscopic monitoring, and is advanced and manipulated so that the flexible tip is guided through the same aperture in the obturator channel which served as the aperture for the obturator, and for the retainer (e.g., the drawstring or loop-retaining thread). Upon completed guidewire advance, the occluded drainage catheter system is withdrawn over the positionally retained guidewire and discarded. An exchange or replacement drainage catheter system (having an obturator pre-installed in its obturator channel) is now inserted by advancing its main drainage lumen along the guidewire until properly positioned, as can be determined by fluoroscopic observation of the distal drainage section of the drainage catheter system within the fluid-collection space of the organ to be drained. The guidewire is withdrawn and the retainer is set. A loop-retaining thread or drawstring retainer is set by being tensioned and clamped so as to form and retain a loop-shaped end section of the drainage catheter system within the fluid-collection space of the organ. A fluid collection bag (or other suitable fluid collection means) is connected by a standard coupling (for example, a so-called Luer Lock) to the main drainage lumen.